Apparatus for electrically killing insects have been known for some time in the prior art as, for example, that disclosed in U.S. Pat. No. 4,121,371 (ELECTRICAL INSECT KILLING APPARATUS) by Elmer Kaphengst et al assigned to the same assignee as this application. The apparatus disclosed in this patent includes a means for attracting insects and electrode means for electrocuting the insects surrounding the attracting means. The electrodes consist of a pair of concentric mesh cylinders arranged vertically and spaced from one another by insulators. Under selective control of a switch, a high electrical potential can be established on the mesh electrodes such that insects passing through the mesh apertures and encountering the electrodes are electrocuted. The mesh spacing is such as to admit insects but prevent entry by small animals, human fingers, and the like. The attactive means include fluorescent tubes emitting wavelengths of light found to be attractive to insects. In operatin of the patented apparatus, it has been found that on occasion the electrocuted remains of the insects falling under the influence of gravity form a bridge between the electrodes and insulator supports resulting in an electrical short.